/*
 * Solo - A beautiful, simple, stable, fast Java blogging system.
 * Copyright (c) 2010-2018, b3log.org & hacpai.com
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
package org.b3log.solo.repository;

import org.b3log.latke.repository.Repository;
import org.b3log.latke.repository.RepositoryException;
import org.json.JSONObject;

import java.util.List;

/**
 * Category repository.
 *
 * @author <a href="http://88250.b3log.org">Liang Ding</a>
 * @version 1.2.0.1, Apr 8, 2017
 * @since 2.0.0
 */
public interface CategoryRepository extends Repository {

    /**
     * Gets a category by the specified category title.
     *
     * @param categoryTitle the specified category title
     * @return a category, {@code null} if not found
     * @throws RepositoryException repository exception
     */
    JSONObject getByTitle(final String categoryTitle) throws RepositoryException;

    /**
     * Gets a category by the specified category URI.
     *
     * @param categoryURI the specified category URI
     * @return a category, {@code null} if not found
     * @throws RepositoryException repository exception
     */
    JSONObject getByURI(final String categoryURI) throws RepositoryException;

    /**
     * Gets the maximum order.
     *
     * @return order number, returns {@code -1} if not found
     * @throws RepositoryException repository exception
     */
    int getMaxOrder() throws RepositoryException;

    /**
     * Gets the upper category of the category specified by the given id.
     *
     * @param id the given id
     * @return upper category, returns {@code null} if not found
     * @throws RepositoryException repository exception
     */
    JSONObject getUpper(final String id) throws RepositoryException;

    /**
     * Gets the under category of the category specified by the given id.
     *
     * @param id the given id
     * @return under category, returns {@code null} if not found
     * @throws RepositoryException repository exception
     */
    JSONObject getUnder(final String id) throws RepositoryException;

    /**
     * Gets a category by the specified order.
     *
     * @param order the specified order
     * @return category, returns {@code null} if not found
     * @throws RepositoryException repository exception
     */
    JSONObject getByOrder(final int order) throws RepositoryException;

    /**
     * Gets most used categories (contains the most tags) with the specified number.
     *
     * @param num the specified number
     * @return a list of most used categories, returns an empty list if not found
     * @throws RepositoryException repository exception
     */
    List<JSONObject> getMostUsedCategories(final int num) throws RepositoryException;
}
